The first record of <i>Gelidium divaricatum</i> (Gelidiaceae, Rhodophyta) in Mexico based on a molecular and morphological approach

SUMMARY The species Gelidium divaricatum was originally described from Hong Kong by G. Martens (1866). Mexico did not have any records of this species until the present study. The species was found from a study for which the research objective is to evaluate specimens of Gelidium collected in Bahía de La Paz, Baja California Sur (the entrance to the Gulf of California) using morphological and molecular techniques, including the rbc L marker. Phylogenetic analyses using the rbc L marker revealed that the studied specimens are in the same clade of G. divaricatum from the type locality with their sequence differences being less than 0.3%, indicating that the specimens are the same species as G. divaricatum . This is the first record of the species for Mexico. The most important morphological difference was the branching pattern, which was irregular to pinnate in the Hong Kong specimens, whereas it was simple or irregular in the Mexican thalli.